Assigxoe of one



(NoModeL) W. M. THOMAS.

REGULATOR FOR SYSTEMS 0F RLROTRIO DISTRIBUTION.

No. 307,690. Patented NOV. 4, 1884.

WITNESSES INVENTOR W223 TVZ'ZZiam M, Thgmg N PETER& Pholn-Lxlhographer. Washington. 04 CI 1 caused by switching lights in or out.

UNITED STATES PATENT @rrrce.

VILLIAM M. THOMAS, OF GRAXD RAPIDS, MICHIGAN, ASSIGNOR OF ONE.- HALF TO THE GRAND RAPIDS ELECTRIC LIGIIT AND PO WER COMPANY,

OF SABIE PLACE.

REGULATOR FOR SYSTEMS OF ELECTRiC DlSTRIBUTlON.

SPECIFICATION forming part of Letters Patent No. 307,690, dated November 4, 1884.

Application tiled March 7, 18: 1.

a lamp or lamps or other consumer of elcctrical energy in a circuit constant, so that, for example, each lamp in acircuit will burn with a uniform or standard candle-power, notwithstanding variation of resistance in the circuit This objectI accomplish effectively by employing a supplemental wire, which accompanies the main-linewirethroughout its circuit,and which I callthe regulating or governing line.

20 This regulating-line is connected with all the switches of the main circuit used to throw in or out the respective lights or other appli auees, and is provided with a resistance at each switch equal to that of each lamp or loop of lamps, as the case may be, so that the resist ance of the regulating-line may be varied when the lamp or loop is thrown into or out of circuit.

My invention relates, primarily, to organizations of the class involving a dynamoelec tric generatorthat is, one in which the geuerated current energizes the field magnet. Heretot'ore in electric lighting systems involving the use of such machines the lamps have 5 been, so far as connect-ionin series is concerned,

either placed directly in the circuit in series, so that when any lamp was cutout the resistance of the external circuit of the generator was decreased, causing an increase in the can 40 dle-powcr of the lamps remaining in the circuit, or they have been placed in series in the circuit and shunted by adjustable resistances.

I am aware that generators working electriclightcircuitshavc been provided with a shunt 5 of adjustable resistance at the generating-station, so that the amount of current passing through the coils of the field-magnet, and consequently the current generated by the machine, could be varied or adj usted to suit the working conditions of the external circuit. I

(No model.)

' do not, therefore, claim, broadly, a shunt of adjustable resistance placed around the coils of the field-magnet ol" the generator; but my in vention contenmlates a novel arrangement of the lamps, the shunt or regulating circuit, and

resistances in said circuit. By my organization the electro-motire force of the generatorcircuit can be controlled at each lamp to compensate for variations of resistance in the main circuit, caused by the switching in and out of lamps, so that a substantially uniform candlepower for each lamp is maintained.

The accompanying drawing is a diagram view illustrating the invention.

A is an ordinary dynamo-electric generator of any of the wcllknown types. 13 isthepositive brush, and G the negative brush. The main circuit is indicated by the solid arrows, and is shown as running from the negative brush (J through the main line and tield-mag- 7o net coils of the generator to the positive brush shunt S is provided with a switch and a resist-ance, It, placed in a loop in the shunt in the same manner that the lamp is placed in the main circuit. Now, if all the switches are closed, so that the direct line of the shunt and main circuit is completed, a shunt of minimum 5 resistance will be completed from the negative brush C by the main circuit (indicated by the solid arrows) to the point a, and then by the shunt- S to the positive brush, so that little, it' any, current will pass through the 9 coils of the held-magnet, and consequently a minimum current will be generated and the amount of work done reduced to the lowest point. Obviously, now, any increase of resistance in the shunt will cause a greater amount of current to pass from the point why the main circuit through the coils of the field magnet, and consequently an increased current will be generated by the machine. It,

therefore, the lamp at L be thrown into the cir- A sluint-circuit, S, 75

may be located, may be operated with like ctcuit by opening its switch and the resistance 1 R be thrown into the shunt, there will be a corresponding increase of the current generated sufficient to maintain thereqnired candlepower at the lamp L. The switches at L and L or any other points in the circuit where lamps feet, and when any lamp is extinguished or cut out of circuit the resistance corresponding to it will also be cut out of the shunt, thus decreasing the resistance of the shunt and con sequently the current generated. The resistances B should be ordinary adjustable resistances, so that they may be regulated to give the desired candle-power to each lamp.

Instead of placing a single lamp in a single branch in the main circuit, as shown atL and L, I may place a number of lampsinmultipleare circuit, as shown at L. These details, as well as others having reference to the relation of resistance to candlepower and such other matters, are subjects of detail for the electrical engineer, and are well understood.

Instead of having switches independently operated, as at If, they may be connected by a suitable cross bar, so as to operate them si multaneonsly, as indicated at L and L, or any other suitable device for simultaneous operation may be employed. Devices also for gradual make and break of the direct circuits by the operation otthe switches may be employed. They are well known, however, and need no description or illustration.

1 have shown my invention as applied to a single dynamo electric generator operating a single lampcircuit. It is obvious, however, that in those systems in which the field-magnets of a number of generators are energized by a primary exciting-generatorthe resistance of the loop or circuit serving to excite the coils of any one machine may be varied in the manner illustrated, and I considersuch an arrangement within the scope otmy invention. It is also obvious that whereanumber ot'loops or independent lamp-circuits are worked from a single generator the shunt may be so arranged with ret'erence to the lighting-circuits that its resistance may be controlled as herein described. In fact, the controlling-circuit,

whatever may be its character, may accompany the lamp-circuit and its resistance be varied, as described, to control the electromotive force of the working-circuit.

I have described my invention as specially applicable to electric lighting; but, as remarked at the beginning of this specification, the same arrangement precisely may be employed for operating motors or other electrical instruments or machines.

I am aware that the patent of Edison, No. 248,422, shows an arrangement of multiplearc circuits for automatically regulating the generative force of the generator by regulating the current energizing the field-of-force coils simultaneously with controlling the lamps; and I do not, therefore, claim such subject-matter broadly.

I claim as my in vention- 1. The combination of an electric generator, lamps, or electric instruments placed in series in the circuit of said generator, an electric conductor or circuit which accompanies the generator-circuit, and the current traversing which regulates the amount of current generated by the machine, and means for varying the resistance of said regulating circuit or conductor at each of the lamps or instruments in' the circuit of thegenerator when one of said instruments is thrown into or out of circuit.

2. The combination of an electric generator in which the coils of the field-magnet are included in the generator-oircuit, electriclam m or instruments placed in the circuit of said generator, at shunt-circuit placed around the coils of the field-magnet and accompanying the circuit in which the lamps or instruments are placed, and means for varying the resistance of the shunt as the instruments are thrown into or out of circuit, for the purpose de scribed.

I11 testimony whereof I have hereunto sul scribed my name this 41th day of March, A l). 1884-.

\V. BI. THOMAS.

Witnesses:

WM. H. lowims, .T. H. hhxnsnam 

